<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>用户登录</title>
    <style>
        body {
            background-color: #fff;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            margin: 0;
        }

       .login-box {
            background-color: #333;
            color: #fff;
            padding: 30px;
            border: 1px solid #fff;
            border-radius: 5px;
            position: relative;
        }

       .login-title {
            text-align: center;
            margin-bottom: 20px;
        }

       .form-item {
            margin-bottom: 15px;
        }

       .form-item label {
            display: inline-block;
            width: 80px;
        }

       .form-item input {
            width: 150px;
            padding: 5px;
            border: 1px solid #ccc;
        }

       .btn-container {
            text-align: center;
            margin-top: 20px;
        }

       .btn {
            padding: 5px 10px;
            margin: 0 5px;
            border: none;
            background-color: #fff;
            cursor: pointer;
        }

       .white-line {
            position: absolute;
            width: 1px;
            background-color: #fff;
        }

       .line-left {
            left: 10px;
            top: 40px;
            height: 80px;
            transform: skewY(-10deg);
        }

       .line-right {
            right: 10px;
            top: 40px;
            height: 80px;
            transform: skewY(10deg);
        }

       .bottom-line {
            bottom: 10px;
            left: 50%;
            transform: translateX(-50%);
            width: calc(100% - 20px);
            height: 1px;
        }

       .left-bottom-connector {
            position: absolute;
            width: 1px;
            background-color: #fff;
            bottom: 10px;
            left: 10px;
            height: 0;
            transform: skewX(-10deg);
        }

       .right-bottom-connector {
            position: absolute;
            width: 1px;
            background-color: #fff;
            bottom: 10px;
            right: 10px;
            height: 0;
            transform: skewX(10deg);
        }
    </style>
</head>

<body>
    <div class="login-box">
        <h3 class="login-title">用户登录</h3>
        <div class="white-line line-left"></div>
        <div class="white-line line-right"></div>
        <div class="white-line bottom-line"></div>
        <div class="white-line left-bottom-connector"></div>
        <div class="white-line right-bottom-connector"></div>
        <form id="loginForm">
            <div class="form-item">
                <label for="username">用户名</label>
                <input type="text" id="username" name="username">
            </div>
            <div class="form-item">
                <label for="password">密码</label>
                <input type="password" id="password" name="password">
            </div>
            <div class="btn-container">
                <button type="submit" class="btn">提交</button>
                <button type="reset" class="btn">重置</button>
            </div>
        </form>
    </div>
    <script src="script.js"></script>
</body>

</html>
